Spark plug



p 1941- I. H. RABEZZANA 2,254,494

7 SPARK PLUG Fiied May 20, 1940 s Sheets-Sheet 1 3nnentor By a Wattorneys Sept. 2, 1941. RABEZZANA SPARK PLUG I Filed May 20, 1940 5Sheets-Sheet 2 (Ittorngs Sept 1941- H. RABEZZANA 2,254,494

SPARK PLUG Filed May 20, 1940 5 Sheets-Sheet 3 a w w attorneys Sept. 2,1941. H. RAB'EZZANA SPARK PLUG Filed May 20, 1940 5 Sheets-Sheet 4Z'snventor 220301 fiafizzzazm M (Ittornegs H. RABEZZANA SPARK PLUG Sept.2, 1941. 4

v 5 Sheets-Sheet 5 Filed Ma 20, 1940 Patented Sept. 2, 1941 SPARK PLUGHector Babemna, Flint, Mich minor to General Motors Corporation,Detroit, Mich, a corporation of Delaware Application, May 20, 1940,Serial No. 836,156

14 Claims. (01- 219-4) less likely to become distorted under the hightemperature conditions present in modern internal combustion engines.and are less likely to mechanical injury, than are shell electrodeswhich have one end only fastened to the shell; they operate at lowertemperatures than prior electrodes wherein one end only is ordinarilyfastened to the shell, because two paths for the flow of heat from thespark gap to the shell are provided instead of a single path; and, beingstronger and more resistant to changes in form incident to inordinatelyhigh temperatures commonly present, and to mechanical injury due tohandling, a more definite and constant length of spark gap is maintainedthan has usually been present in spark plugs whereinone end only of theshell electrode is fastened to the shell of the plug.

The advantages above enumerated and others are secured in my improvedspark plug wherein both ends of the grounded or shell electrode are 7electrically welded to the spark plug shell. The

I advantage of strength. has to be sure been heretofore secured to adegree in prior plugs having shell electrodes of loop or U-shape form,staked or otherwise mechanically fastened to the shell;

and the advantage of better heat conduction from the spark gap to theshell, so far as that end may be secured by a single welded joint, hasbeen sought by electrically welding one end of a shell electrode to theshell; but the simultaneous welding of both ends of such an electrode tothe shell presents various and particular problems in the art of sparkplug fabrication not heretofore solved according to my best information.

My invention therefore comprises the machine hereinafter described andclaimed for electrically welding both ends of loop or U-shapedelectrodes to shells or casings of spark plugs whereby the advantages ofbetter heat conduction, enhanced strength, and less liability to changeof form under the high temperature conditions commonly present aresecured than has heretofore commonly been secured in spark plugs.

part of this specification illustrate the preferred form of myinvention, and therein:

Figure l is a view showing various elements and features of my inventionin side elevation, and others in section. 1

Figure 2 is a view showing the machine wherein-my invention consists inplan.

Figure 8 is a sectional view taken upon a vertical transverse-planeindicated by the line 3-3, Figure 2, and showingcertain details of myinvention. v

Figure 4 is a iragmentary view showing details of a trunnion shait of myinvention, taken upon a verti al transverse plane indicated by thelineH.Figure2.'

Figure 5 is a fragmentary sectional view upon a much larger scale,- thescale of Figures 1 to 4, showing oertain-U sha'ped'shell electrodefeeding mechanism, and welding mechanism cooperating therewith.

Figure 6 is a view like Figure 5 but showing the parts in 'diiferentpositions than they are shown in Figure 6.

Figure 7. is a fra mentary view showing a section upon. atransverselyextending vertical plane indicated by thefl -I, Figure 6.

Figure 8 is a fragmentary view showing a section upon a transverselyextending vertical plane by the line 8-6, Figure 5.

' Figure 9 is airagmentary view showing a section a transverselyextending inclined plane indicated by the line 6-]. Figure 6.

Figure 10 is" a view showing an escapement operating member associatedwith the U-shaped shell electrode feeding mechanism shown in Figures 5and 6, in perspective.

Figure 11 is a view likewise in perspective, showing one of twoescapement members of my device.

Figure 12 is a perspective view showing the lower end of a loopelectrodefeeding bar of my device, down which li-shaped shell electrodes slide. v

Figure '13 is a perspective view showing one of two semi-circularmembers which house various elements of the shell electrode feedingmechanism 01 my invention; H

Referring now to the drawings, the numeral l6 designates a base ofgeneral box-like constructlon and having transverse partition and endwalls l6,- l1 and a bottom wall ll, whereby an oil reservoir is providedwhereby cams upon, a rotatable shaft II, the ends of which are supportedin bearings in the side walls of the base.

The drawings accompanying and forming a are kept supplied with oil. Camscarried by this the numeral 2| designates an annular spark plug shellcarrier carried by, and which is rotatable relative to said member 28.This shell carrier member has a series of radially arranged seats 22adapted to receive spark plug shells 44, as shown, and a series ofperipheral notches 24 arranged in alternation with said seats with whichthe free end of a spring-pressed pawl 28 engages to impart astep-by-step rotary movement to said carrier. This pawl is carried bythe left hand end, Figure 2, of a slide 21 which reciprocates in guides28 carried by the base ii; movement of said slide and pawl toward theleft being produced by a cam 28 upon the shaft i8, and return movementthereof being produced by a tension spring 48. Reverse or backwardmovement of the carrier member II is prevented by a pivotaliy supportedpawl Ii which is acted upon by a tension spring 82.

The supporting member 28 is provided with a radial slot 88; and thenumeral 44 designates a reciprocating spark plug shell lifting membershown as carried by trunnions 35, supported in bearings "I of insulatingmaterial provided in the side walls 38 of the base II, which walls alsosupport bearings for the ends of the cam shaft i8. The left hand end ofthis shell lifting member moves up and down in the slot 33, see Figure1; and the same has a gap, as shown, so that it will not interfere withrotary movement of the carrier member 2|. The right hand end of theshell lifting member 84 carries a roller 3'! of insulating material asshown in Figure 1, which is acted upon by a cam 38 upon the shaft is tomove the left hand end of said member downward against the action of acompression spring 88 and into its lowermost position shown; whichspring returns said member into its uppermost position when the cam 38moves out of engagement' with the roller 81. A buffer 88| of insulatingmaterial is interposed between the lifting member 44 and the upper endof the spring 39, as shown.

The shell lifting member 34 has a pair of shell grasping laws 48, 4|which grasp and hold the spark plug shells 48 during the welding ofgrounded shell electrodes 85 to them, and which jaws are commonly madeadjustable so as to adapt the. machine for operation upon shells ofdifferent diameters; and replaceable by other jaws to adapt the machinefor use with types of shells differing from the particular type shown.The right hand one 4| of these jaws is carried by a reciprocating slide42 which is urged toward the left to grasp a shell and hold it duringthe welding of a shell electrode 55 thereto, by a stiff compressionspring 44 acting against an adjustable abutment 45 within the right handtubular end of the shell lifting member 84, as shown; and a rod 48extends from the slide 42 through the abutment, and has a collar 41 ofinsulating material at its free right hand end, whereby the slide 42 maybe moved against the action of the spring 44 to release the shell 43from the holding action of the jaws 40, 4|.

The rod 48 is moved as aforesaid by an oscillating lever 48 the lowerend of which is supported by a short shaft 48 which in turn is supportedby bearings 88 upon the bottom wall l8; and the upper end 5| of thislever is bifurcated to clear the rod 48, and engages the collar 41. Thelever 48 itself is swung about the shaft 48 at its lower end byduplicate cams 52 upon the shaft N which act upon roller 88 carried by ashort shaft 54 carried by the lever 48.

A spark plug shell 48 is carried by the rotary carrying member 2| into aposition between the Jaws 48, 4| while the jaws are separated by thecams 52 acting through the lever 48 as above explained to compress thespring 44, and while the left hand end of the lifting member 34 is downas shown in Figure 1; the cams 52 next release the lever 48 and permitthe spring 44 to close the Jaws upon the shell and grasp it firmly, dueto the action of said spring; and-following this last action the cam 38runs beyond the roller 11 and permits the spring 48 to move the lefthand end of the lifting member 34 and the shell held between the ;laws44, 4| upward and into the position necessary to accomplish the weldingof the groimded or shell electrode to the shell, heating necessary toaccomplish the welding being due to a current of electricity suppliedthrough leads connected one to the grounded frame of the machine and theother to the lifting member 34 as will be understood.

Figure '1 shows a spark plug shell 43 having a U-shaped grounded orshell electrode 85 the two ends of which are butt welded to the shell bythe machine wherein my invention consists, heating of the two toaccomplish the welding being by a current of electricity made to flowbetween the shell and the electrode and this fi ure and Figures 5 and 6,and 8 to 13, show various features of mechanism for feeding electrodesinto position to be welded to the shell and for electricall weldingtheir free ends to the upper end of the shell, that is to the inner endof the spark plug regarded as in use in an internal combustion englue.

The numeral 56, see Figures 1 and 2, designates a tubular supportingmember shown as cylindrical in form, the same being supported from thebase It by supports 81 and 88; and I8 designates a bearing membersecured in place within said sleeve and which serves as a support for ahollow reciprocating welding member 88 which slides upon theleft handend of said bearing member 88, see Figures 5 and 6. Said welding member88 is operated by a yoke 6| which engages within a circumferentiallyextending groove 82 therein; and said yoke is moved toward the rightagainst the resistance of two tension springs 43, "by two cams 4 carriedby the shaft is, and which cams act upon two rollers 85 carried by twovertically arranged oscillating levers 58 the lower ends of which arepivotaliy supported by pivotal supports 81 adjacent the side walls 38 ofthe base. The upper ends of these levers are connected by a cross bar orrod 48 with the ends of which the right hand ends of the springs 43 areconnected so as to move said cross rod toward the left; andlongitudinally extending tie rods 88, 88 extend between said rod and theyoke 8| as shown in Figure 2. It therefore follows that the cams 84 actthrough the levers 88, cross rod 48 and tie rods 68 to move the weldingmember 68 from the position in which it is shown in Figures 1, 2 and 6toward the right against the resistance of the tension springs 88; andthat said springs move said member from the position in which it isshown in Figure 5 to- '12 which surrounds the left hand end of thebearing member 59 and is secured thereupon by a cross-screw 13. Thismember 19 has an internal seat which receives and holds electrodefeeding means whereby U -shaped grounded or shell electrodes 55 aresupplied to the shells l9 preparatory to being welded thereto, asappears in Figures 6 and 7, said member 19 being split at 14 and theelectrode feeding means being clamped in place within said seat, whichis preferably cylindrical in form, by cross screws 15; the electrodefeeding means being located adjacent the reciprocating welding member 99as will be appreciated.

The electrode feeding means comprises two semi-cylindrical housingmembers 19, 11 which are identical with one another except that they aremade rights-and-lefts, and which housing members are definitelypositioned relative to one another by dowel pins 19, and are securedto-' gether by screws 19; and the meeting longitudinal surfaces of thesemembers in contact with one another and in which the axis of saidelectrode feeding means lies are provided with registering recesseswithin which are housed various elements which cooperate to accomplishthe feeding of the electrodes 55 as next appears.

Extending longitudinally of the housing members 16 and 11 and disposedhalf in one and half in the other is an inclined ledge 99; and thenumeral 9| designates an inclined loop electrode feeding bar of invertedT-shaped form in cross section which rests upon said ledge and is heldbetween vertical side walls 92 of said members 19, 11, and which barextends from beyond the left hand end of said members to a positionadjacent an anvil 93 carried by the reciprocating welding member 99, assee Figures and 6. This anvil, although it is a unitary part of thewelding member 99, is commonly made separate therefrom, of hard steel soas to withstand the severe service required of it. The electrodes slidedown this bar 9| and come to rest upon the anvil 93, and are caughtbefrom sliding down the electrode feeding bar. The reciprocating weldingmember 99 carries a tappet 92 adapted to engage the cross bar 99 as saidmember moves from the position shown in Figure 5 into that shown inFigure 6 to thereby release the lowermost shell'electrode 55 and permitit to slide down the bar 9| from the position in which it is shown inFigure 5, and to cometo rest upon the anvil 93 as shown in Figure 6.

The U-shaped shell electrode feeding means includes also a secondescapement member 93 which is supported within a chamber within thesemi-cylindrical members 19, 11 by a pivot 99 at one of its ends, andthe other end of said member has a transverse pin 95 whereby the freeend 95 thereof may be lifted. When the two escapement members are in theposition shown in Figure 5 downward sliding of the column of electrodesis prevented by the first described escapement member 85 as hereinbeforeappears, the free hooked end 95 of the second escapement member 93 beingheld up above the column by arms 91 extending from the arms 99, andhaving inclined ends which lie beneath the transverse lifting pin 95.When, however, the welding member 99 is moved toward the left the tappet92 engages the cross-bar 99, and the arms 91 release the pin 95 andpermit a spring 99 to swing the free end of the escapement member 93downward, thus arresting downward sliding movement of the column ofshell electrodes as tween the welding member andthe lower end of twocooperating escapement members, the

same being carried by an oscillating shaft 99 the ends 91 of which aresupported in bearings 99 adjacent the lower ends of the housing members19, 11. Said shaft carries also two arms 99, the upper ends of which areconnected by a cross bar 99; and which arms are acted upon by twocompression springs 9|, Figures 5 and 9, to hold the escapement member35 in the uppermost position in which it is shown in Figure 5,

in which it acts to prevent the loop electrodes indicated in Figure 6.This permits the electrode 55 downward movement of which was arrested bythe first escapement member 95, as

tion, I claim and desire to secure by Letters Patent:

1. In a machine for welding loop electrodes to spark plug shells, aninclined bar adapted to receive a loop electrode and down which saidelectrode may slide; a reciprocating welding member having an anvilportion arranged adjacent the lower end of said bar and adapted toreceive a loop electrode fed thereto by said bar; means. for operatingsaid welding member to grasp a loop electrode supported by said anvilportion between said member and the lower extremity of said inclinedbar; a reciprocating lifting member; and means for moving said member tocause a spark plug shell carried thereby to en age both the free ends ofsaid electrode.

2. In a machine for welding loop electrodes to spark plug shells, aninclined bar adapted to support a series of loop electrodes and downwhich said electrodes may slide; a reciprocating welding member havingan anvil portion arranged adjacent the lower end of said bar and adaptedto receive a loop electrode fed thereto by said bar; escapementmechanism for controlling the supply of electrodes one at a time to saidanvil; means for operating said escapement mechanism; means foroperating said welding member to grasp a loop electrode supported bysaid anvil portion between said member and the lower extremity of saidsupporting bar; a reciprocating lifting member; and means for movingsaid member to cause a spark plug shell carried thereby to engage boththe free ends of said electrode.

3. In a machine for welding loop electrodes to spark plug shells, aninclined bar adapted to support a series of loop electrodes and downwhich said electrodes may slide; a reciprocating welding member havingan anvil portion arranged adjacent the lower end of said bar and adaptedto receive a loop electrode fed thereto by said bar; escapementmechanism for controlling the supply of electrodes one at a time to saidanvil; means whereby and through which said escapement mechanism isoperated by said welding member; means for operating said welding memberto grasp a loop electrode supported by said anvil portion between saidmember and the lower extremity of said supporting bar; a reciprocatinglifting member; and means for moving said member to cause a spark plugshell carried thereby to engage both the free ends of said electrode.

4. In a machine for welding loop electrodes to spark plug shells, aninclined bar adapted to support a loop electrode and down which saidelectrode may slide; a reciprocating welding member arranged adjacentthe lower end of said bar and to which a loop electrode is fed by saidbar; means for operating said welding member to grasp a loop electrodebetween said member and the lower extremity of said supporting bar; areciprocating lifting member; and means for moving said member to" causea spark plug shell carried thereby to engage both the free ends of saidelectrode.

5. In a machine for welding loop electrodes to spark plug shells, aninclined bar adapted to support a series of loop electrodes and downwhich said electrodes may slide; a reciprocating welding member arrangedadjacent the lower end of said bar and to which a loop electrode is fedby said bar; escapementmechanism for controlling the supply ofelectrodes one at a time to said welding member; means for operatingsaid welding member to grasp a loop electrode between said member andthe lower extremity of said supporting bar; a rotatable spark plug shellcarrier adapted to support a series of spark plug shells and to supplythem one at a time to a lifting member; means for operating saidcarrier; a reciproacting lifting member adapted to receive a spark plugshell from said carrier and to move it into engagement with both thefree ends of said loop electrode; and means for operating said liftingmember.

6. In a machine for welding loop electrodes to spark plug shells, aninclined bar adapted to support a series of loop electrodes and downwhich said electrodes may slide; a reciprocating welding member arrangedadjacent the lower end of said bar and to which a loop electrode is fedby said bar; escapement mechanism for controlling the supply ofelectrodes one at a time to said welding member; means for operatingsaid welding member to grasp a loop electrode between said member andthe lower extremity of said supporting bar; a non-rotatable supportingmember circular in form and having a radially extending slot; an annularspark plug shell carrier supported by and rotatable relative to saidsupporting member, and adapted to support a series of spark plug shellsand to supply them one at a time to a lifting member; means foroperating said carrier; a reciprocating lifting member movable up anddown in-the slot aforesaid, and which member is adapted to receive aspark plug shell from said carrier and to move it into engagement withboth the free ends of said loop electrode; and means for operating saidlifting member.

'7. In a machine for welding loop electrodes to spark plug shells, meansfor supplying a loop electrode to be welded to said shell; areciprocating welding member arranged adjacent said electrode supplyingmeans; means for operating said welding member to grasp a loop electrodebetween said member and said electrode supplying means; a reciprocatinglifting member; means for moving said member to cause a spark plug shellcarried thereby to engage both the free ends of said electrode; shellgrasping mechanism carried by said lifting member and adapted to graspand hold said spark plug shell; and means for operating said shellgrasping mechanism.

8. In a machine for welding loop electrodes to spark plug shells, aninclined bar adapted to support a loop electrode and down which saidelectrode may slide; a reciprocating welding member arranged adjacentthe lower end of said bar and to which a loop electrode is fed by saidher; means for operating said welding member to .grasp a loop electrodebetween said member and the lower extremity of said supporting bar; areciprocating lifting member; means for moving said member to cause aspark plug shell carried thereby to engage both the free ends of saidelectrode; shell grasping mechanism carried by said lifting member andadapted to grasp and hold said spark plug shell; and means for operatingsaid shell grasping mechanism.

9. In a machine for welding loop electrodes to spark plug shells, asuitable base; a supporting member supported by said base; a bearingmember supported by said supporting member; a reciprocating weldingmember slidable upon said bearing member; means for operating saidwelding member; a second supporting member arranged adjacent saidwelding member; means carried by said second supporting member forfeeding a loop electrode to said welding member; and means for moving aspark plug shell into contact with both the free ends of a loopelectrode grasped between said welding member and said electrode feedingmeans.

10. In a machine for welding loop electrodes to spark plug shells, asuitable base; a tubular supporting member supported by said base; abearing member within said supporting member and extending therefrom; areciprocating welding member slidable upon the end of said bearingmember; means for operating said welding member; a second member alsotubular in form arranged in line with and adjacent to said weldingmember, and which second member is supported by said bearing member;means housed within said second tubular member for feeding a loopelectrode to said welding member; and means for moving a spark plugshell into contact with both the free ends of a loop electrode graspedbetween said welding member and said electrode feeding means.

11. In a machine for welding loop electrodes to spark plug shells, asuitable base; a supporting member supported by said base; a bearingmember supported by said supporting member: a reciprocating weldingmember supported by said bearing member and slidable thereupon; meansfor operating said welding member; a second member tubular in form, andmeans for supporting said second member adjacent said first mentionedsupporting member; means-housed within said second tubular member forfeeding a loop electrode to said welding member; and means for moving aspark plug shell into contact with both the free ends of a loopelectrode grasped between s-aid welding member and said electrodefeeding means.

12. In a machine for welding loop electrodes to spark plug shells, asuitable base; a support ing member supported by said base; a bearingmember supported by said supporting member; a reciprocating weldingmember supported by said bearing member and slidable thereupon; meansfor operating said welding member; a second member tubular in form, andmeans for supporting said second member adjacent said first mentionedsupporting member; two housing members within and extendinglongitudinally of said second tubular member; an inclined bar graspedbetween said housing members and adapted to receive a loop electrode,and down which said electrode may slide to said welding member; andmeans for moving a spark plug shell into contact with both the free endsof a loop electrode grasped between said welding member and the lowerextremity of said inclined bar.

13. In a machine for welding loop'electrodes to spark plug shells, asuitable base; a supporting member supported by said base; a bearingmember supported by said supporting member; a reciprocating weldingmember supported by said bearing member and slidable thereupon; meansfor operating said welding member; a second member tubular in form, andmeans for supporting said second member adjacent said first mentionedsupporting member; two housing members within and extendinglongitudinally 01 said second tubular member; an inclined bar graspedbetween said housing members and adapted to support a series of loopelectrodes, and down which bar said electrodes may slide to said weldingmember; escapement mechanism for controlling the supply of loopelectrodes one at a time to said welding member; means for operatingsaid escapement mechanism; and means for moving a spark plug shell intocontact with both the free ends of a loop electrode grasped between saidwelding member and the lower extremity of said inclined bar.

14. In a machine for welding loop electrodes to spark plug shells, asuitable base; a tubular supporting member supported by said base; abearing member within said supporting member and extending therefrom; areciprocating welding member slidable upon the end of said bearingmember; means for operating said welding member; a second member alsotubular in form arranged in line with and adjacent to said weldinmember; two housing members within and extending longitudinally of saidsecond tubular member; an inclined bar grasped between said housingmembers and adapted to support a series of loop electrodes, and downwhich bar said electrodes may slide to said welding member; escapementmechanism located within said housing members and adapted to control thesupply of loop electrodes one at a time to said welding member; meanswhereby and through which said escapement mechanism is operated by saidwelding member; and means for moving a spark plug shell into contactwith both the free ends of a loop electrode grasped between said weldingmember and'the lower extremity of said inclined bar.

HECTOR RABEZZANA.

